The Immune Tolerance Network is dedicated to the clinical evaluation of novel tolerance-inducing therapies that will re-educate the immune system to eliminate injurious immune responses and graft rejection. The ITN conducts clinical trials that include novel tolerance-inducing therapies for islet cell transplantation and the prevention of graft rejection. In addition, to understand the underlying mechanisms of action of the candidate therapies and to monitor tolerance, the ITN has established state of the art core laboratory facilities to conduct integrated mechanistic studies, and to develop and evaluate markers and assays to measure induction, maintenance, and loss of tolerance in humans.